Data Flow Diagrams

Data flow diagram is a tool that shows the process, flow and external entities in a system. The symbols used to chart the data flow are double square, arrow, rectangle with rounded corners and an open-ended rectangle. The double square is used define an external entity that can send data or receive data from the system. The arrows show the flow of data. The rectangle with rounded corner is used for drawing processes. The open-ended rectangle represents the data stores. Data flow diagrams give further understanding about the system and its subsystem. It also helps  to locate errors in documenting the files.

Entity Relationship Diagram

An entity can be a person, place, thing or an event. Attributes are the description of the entities. Relationship is the interaction of the entities. The different conventions of ERD are Crow’s Foot, Arrow and Bachman notation. ERD creates a graphical representation of the relationship of entities involved in the system. Each relationship can have cardinalities which indicates the number of association of an entity to the other entity. The cardinalities can be one is to one (1:1), one is to many (1:M), and many to many (M:M).

Fishbone Diagram

Fishbone Diagram is a listing of all possible problems that can occur during the study and development of a system. This diagram resembles a fish skeleton. Fishbone diagram Is also known as Cause and Effect diagram and Ishikawa Diagram (Dr. Kaoru Ishikawa). In the head of the fish, the possible problem is listed. The bone of the fish is labeled with categories, the major categories are 4M’s (methods, machine, materials and manpower), 4S’s (Surroundings, suppliers, system, skills), and 4P’s (place, procedure, people, policies).

POS System

Inventory software programs now on the market let you track usage, monitor changes in unit dollar costs, calculate when you need to reorder, and analyze inventory levels on an item-by-item basis. You can even control inventory right at the cash register with point-of-sale (POS) software systems. POS software records each sale when it happens, so your inventory records are always up-to-date. Better still, you get much more information about the sale than you could gather with a manual system. By running reports based on this information, you can make better decisions about ordering and merchandising.

With a POS system:

• You can analyze sales data, figure out how well all the items on your shelves sell, and adjust purchasing levels accordingly.
• You can maintain a sales history to help adjust your buying decisions for seasonal purchasing trends.
• You can improve pricing accuracy by integrating bar-code scanners and credit card authorization ability with the POS system.

There are plenty of popular POS software systems that enable you to use add-on devices at your checkout stations, including electronic cash drawers, bar-code scanners, credit card readers, and receipt or invoice printers. POS packages frequently come with integrated accounting modules, including general ledger, accounts receivable, accounts payable, purchasing, and inventory control systems. In essence, a POS system is an all-in-one way to keep track of your business’s cash flow.

Features to consider in a POS system include the following:

• Ease of use. Look for software with a user-friendly graphical interface.
• Entry of sales information. Most systems allow you to enter inventory codes either manually or automatically via a bar-code scanner. Once the inventory code is entered, the systems call up the standard or sales price, compute the price at multiple quantities and provide a running total. Many systems make it easy to enter sales manually when needed by letting you search for inventory codes based on a partial merchandise number, description, manufacturing code or vendor.
• Pricing. POS systems generally offer a variety of ways to keep track of pricing, including add-on amounts, percentage of cost, margin percentage and custom formulas. For example, if you provide volume discounts, you can set up multiple prices for each item.
• Updating product information. Once a sale is entered, these systems automatically update inventory and accounts receivable records.
• Sales tracking options. Different businesses get paid in different ways. For example, repair or service shops often keep invoices open until the work is completed, so they need a system that allows them to put sales on hold. If you sell expensive goods and allow installment purchases, you might appreciate a loan calculator that tabulates monthly payments. And if you offer rent-to-own items, you’ll want a system that can handle rentals as well as sales.
• Security. In retail, it’s important to keep tight control over cash receipts to prevent theft. Most of these systems provide audit trails so you can trace any problems.
• Taxes. Many POS systems can support numerous tax rates-useful if you run a mail order business and need to deal with taxes for more than one state.

System Analysis and Design, 6^th Edition, Kendall and Kendall

Entrepreneur, http://www.entrepreneur.com/encyclopedia/term/82360.html, accessed on August 5, 2009

The Cash and Inventory System will help the Twenty-Six Twelve Grocery for its transactions and keeping track of its sales and stocks. The system made easy for the cashier to use and save time. The cashier/owner will not having a hard time calculating large quantity of items when a customer buys and he doesn’t need to check the item’s list for the item’s price. The cashier can search the items availability. The system will provide reports of the sales in a day or monthly. For the security of the system, the cashiers/owner has to input a username and password to use the system.

For the customers, they will get the exact change when buying large quantity of items. They don’t have to wait for the Cashier/Owner in computing their purchased because the system will automatically compute the input items. They don’t have to wait for the cashier/owner in looking for the items needed because the system will provide the information of the items availability.

1. Products delivered to customers will be recorded to the inventory system.
2. Customization of manager’s interface.
3. Usage of  item bar code.
4. Printing of receipts for each transactions.